Purkeys Liftgate Double Check User manual

A MISSION CRITICAL ELECTRONICS BRAN
D
LIFTGATE CHARGING SYSTEM
DOUBLE CHECK™
USER GUIDE
INST056 R4.00

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CONTENTS
General Information ..........................................................................................2
Double Check Diagram.....................................................................................4
20 Amp Applied Load Tester Diagram............................................................4
Operating Instructions ......................................................................................5
Connecting to Power Source...................................................................5
Testing the Power Source.........................................................................6
Testing the 7-Way Cable ..........................................................................9
Testing the Ligate Charging System...................................................10
Testing the DC/DC Converter in the Battery Box .............................13
DC/DC Converter Information & Diagnostics ..................................15
Double Check Test Cart: Optional (Example)..............................................17
Double Check Troubleshooting Summary ...................................................19
Tractor without 7-way............................................................................19
Tractor with 7-way..................................................................................20
Testing the Ligate Charging System...................................................21
Testing the DC/DC Converter ..............................................................22
Part List..............................................................................................................23
Limited Commercial Warranty Policy...........................................................28

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e Purkeys Ligate Charging System Double Check™ (Double Check) is
a tool used to test, troubleshoot, or diagnose problems in both the power
source (i.e. tractor) and the ligate charging system on the trailer itself (i.e.
Purkeys Direct™ and Select™ ligate charging systems).
is system is user-friendly and will allow you to use any available vehicle
as a power source. With it, you can test the entire system from tractor to
DC/DC converter in approximately 15 minutes.
Once a proper power source is established, it is simple to test the ligate
charging system. e Double Check tool comes in a case that contains all
the components and adapters you will need to test your trucks/trailers, with
the exception of a multimeter and amp clamp, which your shop should
have.
Here are pictures and descriptions of the most crucial parts and adapters
you will need to test your system:
GENERAL INFORMATION
Ligate Double Check display box 20 amp applied load
Input adapter with alligator clips
(connects to power source)
Input adapter for the 7-way
(connects to power source)

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LIFTGATE DOUBLE CHECK USER GUIDE
7-way output adapterDC/DC inverter harness
Multimeter, leads, and amp clamp: NOT included in kit

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DOUBLE CHECK DIAGRAM
20 AMP APPLIED LOAD TESTER DIAGRAM

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LIFTGATE DOUBLE CHECK USER GUIDE
OPERATING INSTRUCTIONS
e Double Check can use any available vehicle as a power source (i.e. car,
tractor), as long as the vehicle has a 12 V battery and an alternator. However,
if a tractor is being used as the source, it is critical that you ensure that no
part of the tractor is touching the trailer—it cannot be coupled with, or even
touching, the trailer—as the 5th wheel ground path will cause inaccurate test
results.
CONNECTING TO THE POWER SOURCE
Table 1: 20 Amp Applied Load Tester LED Status
LED STATUS
Solid Green Applied Load is ready to test power source
Solid Red Source is being tested
Blinking Red Applied Load is resetting
e 20 Amp Applied Load Tester is used to test the power source. It is crucial
to test the source while under a load to ensure it can provide the proper
voltage needed. Do not assume the vehicle is an adequate source, as a faulty
source may cause a misdiagnosis of the ligate charging system due to an
inadequate power source.
When using the 20 Amp Applied Load, connect the tool to the Double Check
and the power source and make sure the vehicle is running. e Test Status
LED on the 20 Amp Applied Load Tester will turn on. See Table 1 for LED
indications.

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Step 1: Select a vehicle to be used as
the power source and determine
the appropriate input adapter:
• Battery input adapter
• 7-way adapter (if testing with a
7-way cord, see section Testing
the Source Vehicle with a
7-Way Cord)
• Dual pole adapter
• Dual pole female adapter
• Single pole adapter
• Single pole female adapter
Step 2: Connect the 20 Amp Load
Tester to the output side of the
Double Check test display box.
TESTING THE POWER SOURCE
Step 3: Connect the multimeter
leads to the ports on the bottom of
the Double Check test display box
and to your multimeter.

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LIFTGATE DOUBLE CHECK USER GUIDE
Step 4: Connect the 7-way input
adapter to the Double Check to
test the power source (i.e. tractor).
Step 5: Move to the rear of the
tractor and remove the 7-way
cable from the receptacle and plug
the 7-way input adapter into the
tractor.
Step 6: Aer connecting the adapter,
turn the multimeter to “VOLTS
DC” and start the tractor. If the
tractor is functioning correctly, the
large LED on the 20 amp applied
load test box will illuminate solid
green and the voltmeter should
read above 13.2 volts. Record the
voltage.
IMPORTANT NOTE: If the large LED on the test box is not solid green, or if
the voltmeter reads below 13.2 volts, the voltage output is not sucient and
further tractor diagnosis is required.

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Step 7: Press the START button on
the 20 amp applied load test box.
e display box LED will be solid
red to show there is a 20 amp draw
on the tractor and the voltmeter
should read higher than 12.0 volts.
Record the loaded voltage.
IMPORTANT NOTE: If the voltmeter reads below 12.0 volts, the power
source is not sucient and further tractor diagnosis is required.
Step 8: If the tractor has passed up to this point, move on to the next test.